Glucocerebrosidase from human placenta will be purified to homogeneity. This will be achieved by combining a series of conventional and affinity chromatography steps which have already been developed in this laboratory with additional procedures such as new affinity chromatographic steps, preparative isoelectric focusing, preparative acrylamide gel electrophoresis, or lectin chromatography. The subunit structure of the enzyme will be determined. Antibody will be raised against the purified enzyme, and be used to determine whether cross-reacting material (CRM) is present in spleen tissue from patients with Gaucher's disease. A model system for the study of uptake of purified glucocerebrosidase by monocytes is being devised. Using this system, the uptake of enzyme by monocytes from patients with Gaucher's disease will be investigated, offering the macrophages either enzyme in solution, enzyme in liposomes, or enzymes entrapped in resealed erythrocytes. The persistence of enzyme which has been taken up in Gaucher's disease monocytes and hydrolysis of stored glucocerebrosidase in monocytes will be investigated. Further enzyme replacement trials will be conducted using, as enzyme carrier, the preparation which proves to be optimal in the in vitro macrophage system. Plasma from patients with chronic renal disease of unknown origin will be screened for deficiency in alpha-galactosidase to determine whether some patients with chronic renal disease actually have formes fruste of Fabry's disease.